Questions Corrections 2023

Question 1

Plan a method the scientist could use to show that the sample of medicine contains potassium ions and bromide ions
Give the results of the tests

Answer 1

(To test for potassium ions) Place sample of on a wire
Introduce a blue flame using a Bunsen burner
If lilac flame colour is observed potassium is present

(To tea for bromide ions)
Dissolve sample in distilled water in a test tube and add nitric acid
Add silver nitrate using a dropping pipette
Observe cream precipitate
Which shows presence of bromide ions

Question 2

Which instrumental method could be used to show the presence of potassium ions in the medicine and its advantage

Answer 2

Flame emission spectroscopy
More accurate

Question 3

Why would an increase in population cause an increase in CO2 concentration

Answer 3

Increased population so more energy required
So more fossil fuels burned

Question 4

Give one reason why some scientists do not accept the theory that an increase in CO2 has caused the mean temperature of earths atmosphere

Answer 4

There may be other reasons for changes in the temperature

Question 5

Describe a test to show the presence of copper ions in a solution of copper sulfate

Answer 5

Add sodium hydroxide
The result is a blue precipitate